One of the major goals of this project is to identify genetic loci that may contribute to the complex phenotype of antisocial drug dependence phenotype. This requires collection of phenotypic and genotypic data on thousands of individuals. The Core is responsible for DNA collection, storage, and genotype analysis for all components. The core has been carrying out these functions for the past 4 years and has prepared over 7000 buccal cell-derived DNA samples and collected over 350,000 genotypes. Techniques currently in use in the facility include: Buccal cell DNA preparation using commercial kits (Gentra Systems);. Genotyping, using the ABI Prism MD-10 microsatellite marker set; zygosity testing using 11 markers selected from that set; DNA storage and maintenance using computer-based management tools. In addition, the core is currently evaluating the cost and efficacy of switching to microarray-based genotyping and will adopt such new technology only if cost effectiveness and information content is improved. With the addition of a molecular component aimed at identification of genes associated with this complex phenotype, the Core will take on the added role of identification of gene polymorphisms using well-described standard high-throughput methods.